Resveratrol Favors Adhesion and Biofilm Formation ofLacticaseibacillus paracasei subsp. paracaseiStrain ATCC334

Bacterial strains of the Lactobacillaceae family are widely used as probiotics for their multifaceted potential beneficial properties. However, no official recommendations for their clinical use exist since, in many cases, oral administrations of these bacteria displayed limited beneficial effects in human. Additional research is thus needed to improve the efficiency of existing strains with strong potential. In this context, we assess in vitro the effects of nine polyphenols to stimulate biofilm formation by lactobacilli, a feature enhancing their functionalities. Among these polyphenols, we identify trans-Resveratrol (referred to hereafter as Resveratrol) as a potent inducer of biofilm formation byLacticaseibacillus paracasei(formerly designated asLactobacillus paracasei) ATCC334 strain. This effect is strain-dependent and relies on the enhancement ofL. paracaseiadhesion to abiotic and biotic surfaces, including intestinal epithelial cells. Mechanistically, Resveratrol modify physico-chemical properties of the bacterial surface and thereby enhancesL. paracaseiaggregation, subsequently facilitating adhesion and biofilm development. Together, our in vitro data demonstrate that Resveratrol might be used to modulate the behavior of Lactobacilli with probiotic properties. Combination of probiotics and polyphenols could be considered to enhance the probiotic functionalities in further in vivo studies.